Profile

Tonkin snub-nosed monkeys measured to date have weighed about 8 kg (18 lb) (3 females)
and 15 kg (32 lb) (one male). The Tonkin snub-nosed monkey is found mainly in primary
subtropical lowland broadleaf forest on steep limestone hills. Its diet consists primarily
of leaves (including the leaves of bamboo) and
fruits. The Tonkin snub-nosed monkey is exclusively arboreal.
The basic social unit is a one-male group comprised of one adult male, several females and
young animals. Other males form all-male bachelor groups .

The Tonkin snub-nosed monkey is endemic to a
relatively small range in northern Vietnam. In
1947 it was reported to have occurred only in forest near the Song-Koi River. Subsequently
it was thought to be possibly extinct until its rediscovery in 1989. In 1993 it was
reported to occur only in Tuyen Quang and Bac Thai provinces. Historical records have
shown that it once inhabited 5 provinces: Tuyen Quang, Cao Bang, Yen Bai, Bac Thai and
Quang Ninh.

The decline of the Tonkin snub-nosed monkey is due mainly to habitat loss from both
permanent and shifting cultivation as well as hunting for meat and for use in Oriental
medicine. It is also thought to have been affected by military activity in its range. More
than 70% of its original habitat had been lost by 1986.

Tidbits

*** This species lives in remote, mountainous areas. People in these areas are poor,
and typically are unaware of the laws protecting endangered animals. (Ren et al. 1997)

*** After being briefed by biologists on threats to the Tonkin snub-nosed monkey,
community-based district committees in Vietnam,
composed of respected village and community leaders, banned hunting of the species in the
vicinity of one of the best sites remaining in its range. (Karesh 1994)

History of Distribution:

The Tonkin snub-nosed monkey is endemic to a
relatively small range in northern Vietnam. In
1947 it was reported to have occurred only in forest near the Song-Koi River (Tate 1947). Subsequently it was thought to be
possibly extinct until its rediscovery in 1989. In 1993 it was reported to occur only in
Tuyen Quang and Bac Thai provinces (Ratajszczak
et al. 1993). Historical records have shown that it once inhabited 5 provinces:
Tuyen Quang, Cao Bang, Yen Bai, Bac Thai and Quang Ninh (Boonratana & Le Xuan Canh 1998a).

Threats and Reasons for Decline:

The decline of the Tonkin snub-nosed monkey is due mainly to habitat loss from both
permanent and shifting cultivation as well as hunting for meat and for use in Oriental
medicine. It is also thought to have been affected by military activity in its range. More
than 70% of its original habitat had been lost by 1986 (Boonratana & Le Xuan Canh 1998a, Davies & Oates 1994).

Data on Biology and Ecology

Habitat:

The Tonkin snub-nosed monkey is found mainly in primary subtropical lowland broadleaf
forest on steep limestone hills. Plant species in its habitat include figs, dipterocarps, oaks, magnolias and maples.

Diet:

The Tonkin snub-nosed monkey's diet consists primarily of leaves (including the leaves
of bamboo) and fruits. 60 species of plants are
utilized. Food choice varies with the season: young leaves are a primary component of the
diet in Spring (February - May), and fruits are a primary component of the diet in Autumn
(August - October). (Cao Van Sung & Pham
Nhat 1994, Ren et al. 1997)

Behavior:

The Tonkin snub-nosed monkey is exclusively arboreal,
usually traveling at canopy level. There are no
reports of it being able to swim.

Social Organization:

The basic social unit is a one-male group. Each one-male group is composed of one fully
adult male, several females and young animals. The average size of one-male
groups was 15.2 individuals in one study. Extra males form all-male bachelor
groups. The one-male groups frequently come together at sleeping sites and feeding trees
and sometimes travel together. Bachelor groups also associate with these collections of
groups. (Boonratana & Le Xuan Canh
1998, Ren et al. 1997)